This handles the case where `COLOR` is set to some ANSI-like color
sequence in the ambient environment. These sequences tend to include `;`
which terminates the command and tries to use the next component
(typically an integer, possibly with a trailing `m`) with errors like:
/bin/sh: line 1: 2: command not found
/bin/sh: line 1: 255: command not found
/bin/sh: line 1: 221: command not found
/bin/sh: line 1: 255m: command not found
Also add a test that sets `COLOR` in the environment which affects the
generated Makefiles behavior.
See: https://discourse.cmake.org/t/cmake-failing-gcc-compiler-checks/8277
CMake Tests Directory
*********************
This directory contains the CMake test suite.
See also the `CMake Source Code Guide`_.
.. _`CMake Source Code Guide`: ../Help/dev/source.rst
Many tests exist as immediate subdirectories, but some tests
are organized as follows.
* ``CMakeLib/``:
Source code, used for tests, that links to the ``CMakeLib`` library
defined over in ``Source/``.
* ``CMakeOnly/``:
Deprecated. Tests that run CMake to generate a project but not build it.
Superseded by ``Tests/RunCMake/``.
* ``Find*/``:
Tests for specific find modules that can only be run on machines with
the corresponding packages installed. They are enabled in
``CMakeLists.txt`` by undocumented options used on CI builds.
* ``Module/``:
Tests for specific CMake modules.
* ``RunCMake/``:
Tests that run CMake and/or other tools while precisely checking
their return code and stdout/stderr content. Useful for testing
error cases and diagnostic output.